جستجوی مقالات مرتبط با کلیدواژه "whitefly" در نشریات گروه "گیاهپزشکی"

The purpose of the current research is treatment of cotton seeds with appropriate pesticides and foliar application with plant compounds in a way that be effective in control of first-season sap sucking pests in cotton fields. This experiment was designed to study the effect of several treatments including: 1-seed treatment with Thiamethoxam (Cruiser®), 2-seed treatment with Thiodicarb (Larvin®), 3-seed treatment with Imidacloprid (Gaucho®), 4-foliar application of insecticidal soap containing coconut oil (Palizin®), 5-foliar application of botanical insecticide containing pepper extract (Tondexir®), 6-foliar application of imidacloprid (Confidor®), and 7-control for control of first-season sap sucking pests in cotton fields. This research was carried out in a randomized complete block design with five replications at Darab Agricultural Research Station during two years (2020 and 2021). Seed treatments with Larvin® and Gaucho® were applied only in the second year of experiment. The results of the first year of the experiment showed that the cotton seed treatment with Cruser® kept the cotton seedlings free from the cotton aphid (Aphis gossypii Glover) until one month after the sowing date compared to other treatments that were applied as foliar spraying. The results of statistical analysis 41 days after sowing date showed that the most effective control method of onion thrips (Thrips tabaci Lindeman) is seed treatment with Cruiser®. The results of the second year of the experiment showed that Cruzer®, Larvin®, and Gaucho®, which were impregnated with cotton seeds, caused a significant decrease in the population density of cotton whitefly nymph [Bemisia tabaci (Gennadius)] until the end of the sampling period (41 days after sowing date). Foliar spraying of seedlings with herbal compounds (Palizin® and Tondexir®) in both years initially had a significant effect on reducing the population of aphids and whiteflies, but with increase of the time, their effect was less than other treatments. Based on the results of the present research, seed treatment with Cruzer® not only offers more control against cotton seedling sucking pests (onion thrips, cotton aphid and cotton whitefly), but also can be a better option in terms of economy, user's health and environmental effects.

Greenhouse whitefly Trialeurodes vaporariorum is a polyphagous and economically important pest throughout the world. In this study effect of the feeding of predatory bug Macrolophus pygmaeus and spraying of a free amino acid (Delphan Plus®) on biological parameters of the greenhouse whitefly on two cultivars of bean (Azna and Guli cultivars) and cucumber (Kish and Super Star cultivars) as well as the effect of the treatments on parasitation rate by Encarsia formosa were evaluated. Mean comparisons showed that the highest and lowest percentages of whitefly establishment were related to the treatments with predator and Delphan Plus in (Kish: predator 10.93 and Delphan 1.59) respectively, while the highest reduction in establishment was obtained on the Azena bean variety (with Delphan: 0.75) and Super Star variety on the cucumber (with Delphan: 0.81). Also, Delfan Plus has significantly reduced the percentage of herbivore eggs survival on both cucumber and bean varieties compared to the corresponding control as well as reduced the number of nymphs per female in the treatments. In addition, the number of adults that appeared per female decreased in treatments with Delphin Plus in the cultivars of both plants compared to the control. Regarding the parasitization percentage, the interaction effects bilateral interactions of plant-predator, plant-Delphan plus and predator- Delphan plus were also observed. In general, the effect of all the mentioned bilateral intractins caused an increase in the percentage of parasitization of third and fourth instar nymphs by E. formosa in the treatments compared to the control.

Greenhouse whitefly (Trialeurodes vaporarium</em>) Westwood is one of the most important plant pests in Iran and the world. Due to the resistance of whiteflies to common insecticides and the harmful nature of these insecticides to the environment, new and safe compounds should be sought to combat this pest. Epile's new insecticide with a new combination while controlling this pest is also less dangerous for the environment Based on the Bioassay results, LC30 is considered a lethal concentration. The LC30 levels for the insecticides Epile, Abamecetin and Omidochloroprid were 1.31, 0.00448 and 0.00868 mg/lit. The results showed that the application of sub-lethal concentration of the treatments by spraying reduces the length of egg hatching period for the insecticides of Epile, Abacmetin and Omidchloroprid by 11.33, 5.45 and 4.53%, respectively, compared to the control and Epile is less than the length of the egg-related insecticide period. Also, Epile insecticide increased the length of  the larva period by 5.13% and the pupa period by 0.62% compared to the control. Also, the lifespan of adult insects was reduced by 38.64%, and in general, it reduces the lifespan of whitefly.

Due to the effects of overuse of chemical pesticides and the residual problems in greenhouse products that threaten the health of consumers and exports, the use of low-risk alternatives such as plant compounds and biological agents has become necessary. Therefore, in this research, the effect of three commercial formulations of neem plant  (Azadirachta indica A. Juss.) composition, including Nimbecidine, NeemAzal T/S and Kofa was evaluated on the biological stages of Trialeurodes vaporariorum (Hem.: Aleyrodidae), and its parasitoid, Encarsia formosa Gahan. In evaluating the lethal effect of three commercial formulations, the highest lethal effect on eggs after 7 days related to Nimbecidine formula with LC50 equal to 774.71 ppm. The highest lethal effect on 3rd nymphal stage and adult whitefly after 72 hours with LC50 equal to 402.89 and 655.51 ppm in Nimbecidine formula were observed, respectively. A similar effect was obtained on parasitoid. In evaluating the oviposition preference of E. formosa for by choice and non-choice methods, the tendency of E. formosa to control was more than the formulas. The highest probability of oviposition of parasitoid in Kofa formula was observed (%42.66). The results of this study showed that all three formulas can be used in integrated management of this pest and when the emergence and use of E. formosa parasitoid, Kofa formula and in the absence of parasitoid, Nimbecidine formula is recommended.

Greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is a serious pest of a wide range of plants, such as common bean, cucumber, tomato, pepper, lettuce, etc, in both field and greenhouse production. It typically feeds on the underside of leaves, sucking phloem sap from the plant, which causes both direct damage, by overall weakening the plant and reducing yield, and indirect damage, by excreting honeydew, on which sooty mold grows, as well as transmission of several plant viruses. The widespread use of insecticides to control T. vaporariorum has resulted in developing resistance to the insecticides and affected human’s health and safety. The utilization of plant extract and elicitors is an environmentally safe method that is used in the control recently. Therefore, alternative control strategies are required to minimize the harmful effects of insecticides. In order to control this pest, environmentally friendly methods, especially of plant origin are recently considered by researchers. For this regard, the effect of some organic compounds including methanolic and n-hexanic extract of walnut’s husk or dill’s seeds and salicylic acid, individually and in combination with spirotetramat on population density of greenhouse whitefly’s nymphs and some secondary compounds of bean plant were investigated.
Seeds of common bean, Phaseolus vulgaris L. (Berloty cultivar) were sown and grown in 15-cm-plastic pots in a greenhouse at 25 ± 3°C, 50 ± 10% RH, and a natural photoperiod. For the experiments, potted bean plants at 6-8 leaf stage, highly infested with T. vaporariorum nymphs, were sprayed with 12 different treatments, including: (1) spirotetramat (SP), (2) methanolic extract of walnut husk (MW), (3) n-hexanic extract of walnut husk (NW), (4) methanolic extract of dill seed (MD), (5) n-hexanic extract of dill seed (ND, (6) salicylic acid (SA), (7) spirotetramat in combination with salicylic acid (SP+SA), (8) spirotetramat in combination with methanolic extract of dill seed (SP+MD), (9) spirotetramat in combination with methanolic extract of walnut husk (SP+MW), (10) spirotetramat in combination with n-hexanic extract of dill seed (SP+ND), (11) spirotetramat in combination with n-hexanic extract of walnut husk (SP+NW), and (12) water as a control (CO). After five days, the population density of T. vaporariorum nymphs on bean plants leaves was recorded. Furthermore, the effects of tested treatments on the total phenol and flavonoid contents of bean plants were evaluated. For this reason, dried leaves (5 g) from each treatment were used for the preparation of extracts. The total phenolic of the extracts were determined using the Folin - Ciocalteu reagent. Sample and standard readings were made using a spectrophotometer (Lambda 45-UV/Visible) at 765 nm against the reagent blank. Furthermore, the aluminum chloride colorimetric method was used for determination of the total flavonoid content of treatments. For total flavonoid determination, quercetin was used to make the standard calibration curve. The absorbance was read using a spectrophotometer (Lambda 45-UV/Visible) in the wavelengths of 415 nm. Data were analyzed by one-way ANOVA using SPSS 23.0 software. Comparison of means for nymph density using SNK (Student-Newman-Keuls) multi-range test and comparison of means for secondary chemical compositions using Tukey's test at probability level five Percentage occurred.
Results showed that the population density of greenhouse whitefly and the secondary metabolites of plant were significantly affected by the tested treatments. The lowest number of whitefly’s nymphs was on spirotetramat and spirotetramat in combination with methanolic extract of dill seed and the highest number was on control. Total phenolic contents ranged from 58.96 to 114.07 mg g-1 dry weight on different treatments, which the highest and lowest amount of it was obtained in spirotetramat in combination with methanolic extract of dill seed and spirotetramat in combination with n-hexanic extract of walnut husk, respectively. The highest amount of total flavonoid content of bean plants was in spirotetramat in combination with salicylic acid. The results of the present study showed that the density of greenhouse whitefly population in spirotetramate treatment was lower than other treatments but there was no significant difference with the combined treatments and methanolic extract of walnut husk. Also, all the treatments compared to the control significantly changed the population density of this pest and increased the amount of total phenolic compound in bean plant. Therefore, these compounds, especially the methanolic extract of walnut husk, can be used in integrated management programs of this pest.
This research could provide valuable information for control of T. vaporariorum in other plants like ornamental plants in the field and greenhouse and thus can be useful for the production of healthy and organic crops. So it can be used in the IPM programs of this pest.

The greenhouse whitefly, Trialeurodes vaporarium (Westwood), is an invasive insect pest of agriculture and horticulture worldwide. Imidacloprid as chemical pesticide has been used as a key pesticide for controlling sap-sucking pests and play a major role in controlling this pest. The main purpose of this study was investigation of resistance status of T. vaporarium to imidacloprid SC 35% (Confidor®) and cross resistance to Eforia® and Proteus® and effect of imidacloprid resistance on Encarsia formosa Gahan. Thirteen greenhouse whitefly populations were collected from greenhouses and fields and used for tests. Collected populations reared on cucumber plants under laboratory conditions at 25±2˚C, 70±10 % relative humidity and a photoperiod of 16:8 h (L: D). The LC50 values were estimated on the second instar nymphs for all populations using leaf dipping bioassay method. The VGR population showed highest LC50 that was 856.2 mg/L. The development of resistance to imidacloprid was confirmed for all tested populations with resistance factors ranging from 2.54 to 44.3. The most resistant strain showed cross resistance to Eforia® and Proteus®. There was no significant difference between LC50 values of E. formosa populations that collected form field, reared on the most resistant population and sensitive population of T. vaporarium. The LC50s were 388.7, 324.7 and 317.7, respectively. We discuss our results in regard to the evolve of imidacloprid resistance in T. vaporariorum populations and its implications for whitefly control.

Whitefly (Trialeurodes vaporariorum West.) as a polyphage greenhouse pest with a large number of generations is one of the most important crop and greenhouse pests. In this study, the toxicity of emamectin, spinosad, buprofezin and imidacloprid on greenhouse whitefly and parasitoid wasps Encarsia formosa was investigated. The LC50 values obtained from the probit analysis of bioassay data as a result of the effect of different concentrations of emamectin, spinosad, buprofezin and imidacloprid on 3rd nymph stage of greenhouse whitefly after 24, 48 and 72 hours were (1.72, 1.33, 1.31 and 0.63), (1.40, 1.31, 1.27 and 0.44) and (1.15, 1.04, 0.93 and 0.31) ml L-1, respectively. According to these results, the most effective insecticide on 3rd nymph of whitefly was imidacloprid during 24, 48 and 72 hours and the least effective insecticide was emamectin. The results of analysis of variance and comparison of mean mortality due to treatments of emamectin, spinosad, buprofezin and imidacloprid on E. formosa after 5 days showed that buprofezin was the least dangerous and imidacloprid was the most dangerous insecticide for this natural enemy.Therefore, in integrated management of this pest, due to the ineffectiveness of buprofezin on E. formosa in comparison with other insecticides and also having high toxicity on the egg and 3rd nymph stage of the pest is recommended.

Whiteflies and thrips are important pests that active in cotton fields and in addition to direct damage, they alsoindirectly reduce quantity and quality of oilseeds. Orius niger (Wolff) (Hem.: Anthocoridae) is one of theoptimal biocontrol agents for thrips and whiteflies, which is abundant in oilseed fields, especially cotton fields ofGolestan province. In order to evaluate the predatory efficiency of O. niger, this insect was collected from cottonfields and grown in laboratory conditions. In experiments related to the study of predatory; for each predator(female), whitefly densities of 5, 10, 20, 30 and 40 nymphs, 5, 10, 20, 30 and 50 eggs and 5, 10, 20, 30 and 40thrips nymphs were placed in the Petri dish. The results of logistic regression showed that the functionalresponse model is type III for both egg and nymph stages of whitefly and type II for nymphs of thrips. For thripsnymphs, eggs and nymphs of whitefly, according to Roger's equation, calculated searching efficiency parameter(a′) was 0.0697, 0.01193 and 0.01072 /h, and handling time (Th) was 0.3802, 0.2686 and 4.1042 hours,respectively. Prey preference experiments were calculated using the Manley's formula. Manley index of thripslarvae (prey I) and whitefly eggs (prey II) were 0.92 and 0.08, respectively, and for thrips larvae (prey I) andwhitefly nymphs (prey II) were 0.85 and 0.15 which shows that this predator significantly prefers thrips larvae tothe other two preys. In general, the results showed that O. niger can be used as a favorable biological controlagent for thrips in cotton fields.

 Bemisia tabaci (Genn.)(Hem: Aleyrodidae)is considered as one significant pest in the agricultural products in Iran. In this research, the effects of ZnO NPs, kaolin, B. bassiana (EUTP105 Isolate) were assessed alone or in combination to Neemarin® compared to thiacloprid insecticide under field conditions on eggs and nymphs of B. tabaci and pupae of its parasitoid Eretmocerus mundus.

This research was handled in the research field of the scientific staff of the Cotton Research Center of East Iran, Kashmar, in a randomized complete block design with three replications in August 2019. The experimental plots were separately 6 m2 and 1.5 m. The recommended concentration of Neemarin® (15 mg L-1 AZA), thiacloprid (0.3 mL L-1), Kaolin (30 g L-1), a concentration of 20 mg L-1 of ZnO NPs, a concentration of 1×1010 conidia mL-1 of B. bassiana, half- concentration of Neemarin® (7.5 mg L-1 AZA) + 10 mg L-1 of ZnO NPs, half- concentration of Neemarin® (7.5 mg L-1 AZA) + 15 g L-1 of Kaolin and half- concentration of Neemarin® (7.5 mg L-1 AZA) + a concentration of 1×105 conidia mL-1 of B. bassiana were prepared which sprayed on upper and lower surfaces of cotton plants using a knapsack sprayer, equivalent to an application volume of 500 l ha-1. The control treatment was sprayed by water. The mortality of B. tabaci eggs and nymphs and pupal stage of E. mundus were calculated using Henderson and Tilton equation . To this purpose, five plants were randomly selected in each plot and three leaves from each one (top, middle, and bottom section of plant canopy) were excised and transferred to a laboratory. Two pieces of 1 cm2 from each leaf were chosen so that the units included into main vein. Total live eggs and nymphs of pest as well pupae of parasitoid in each sample unit were counted using a binocular. Samplings were handled one day before and 3, 7 and 14 days after spraying.

In 3 DAT (days after treatment), the most effective treatments on eggs and nymphs of pest were Kaolin + Neemarin® and thiacloprid, respectively. While, the least effective treatments were B. bassiana. In 7 DAT, Kaolin + Neemarin® and ZnO NPs exerted the highest and lowest mortality, respectively, on the eggs of pest, Neemarin® and B. bassiana exerted the highest and lowest mortality, respectively to the nymph. In 14 DAT, the highest efficacy on eggs and nymphs was observed in Kaolin + Neemarin® and Neemarin®, respectively, while the lowest efficacy both on eggs and nymphs belonged to B. bassiana. The highest and lowest mortality of the pupae of parasitoid in 3 DAT belonged to thiacloprid and B. bassiana, respectively. In 7 DAT, Neemarin® and ZnO exerted the highest and lowest mortality on the parasitoid pupae, respectively.  In 14 DAT, Kaolin exerted the highest mortality on the pupae of parasitoid that was followed by Kaolin + Neemarin®, Neemarin®, and thiacloprid. The maximum yield and benefit/cost ratio were observed in Kaolin + Neemarin®, followed by Kaolin treatments. 

Considering the results, ZnO NPs and Kaolin alone, or in combination to Neemarin® can be the suitable candidates as an alternative in the IPM programs of B. tabaci on the cotton field.

Predatory mite Amblyseius swirskii Athias-Henriot is one of the most important species of Phytoseiidae. In the current study, the effects of feeding on different preys including two-spotted spider mite Tetranychus urticae Koch, cereal mite Tyrophagus putrescentiae (Schrank), silverleaf whitefly Bemisia tabaci (Gennadius); together with integrated treatments of these preys including spider mite+cereal mite, spider mite+whitefly, cereal mite+whitefly and spider mite+cereal mite+whitefly on the biological charactristics of adult females of this predator (predation, fecundity and survivorship) were investigated after seven days storage at 10 °C. Larva and adult female with 72.34 and 11.76 % mortality had the highest and lowest susceptibility of this predator to temperature of 10 °C, respectively. The highest feeding of predatory mite after cold storage was observed on the larva and protonymph of T. urticae (91.63 prey). The lowest feeding was recorded on eggs of cereal mite (10.18 prey). Total fecundity of the predatory mite was significantly affected by different prey; the highest (5.13 egg) and lowest (1.55 egg) values of this parameter were recorded when the predatory mite fed on “spider mite+cereal mite+whitefly” and “cereal mite”, respectively. In the view point of mortality, the highest percentage was recorded in the predatory mites that reared on the cereal mite. According to the results obtained, integrated treatment of “spider mite+cereal mite+whitefly” was the most suitable treatment for the storage of A. swirskii at cold conditions than other treatments tested.

The sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is an economically important pest of a variety of agricultural crops worldwide. The control of sweet potato whitefly largely relies on the use of synthetic insecticides. However, the efficiency of chemical control is questionable with respect to the activity of adults and immatures on the abaxial surfaces of leaves. In addition, under the strong selection pressure of the chemical control, whitefly populations have become resistant to most registered insecticides. Therefore, the search for more environmentally friendly options for whitefly control is necessary. Botanical extracts are broad-spectrum materials, used in pest control and they compared to synthetic ones may be safer for the environment, are, generally, less expensive and are often decomposed to nontoxic products. They are potentially suitable for use in integrated pest management. Recently, in addition to the botanical insecticides, vermicomposting has been also proposed as a safe control method for insect pests. Vermicompost is an organic soil amendment, produced by earthworm digestion of organic waste. Studies show that plants grown in soil amended with vermicompost grow faster, are more productive and are less susceptible to a number of arthropod pests. In this research studied the mortality effect of ethanol extracts of the seeds and leave of Ricinus communis L. (Euphorbiaceae), Sophora alopecuriodes L. (Fabaceae), Aloe vera (L.) (Liliaceae) on adults of B. tabaci that reared on a tomato that planting in vermicompost from two different sources (pistachio waste and cattle manure). This result was compared with the insecticide abamectin.

The experiments were carried out in a completely randomized design and in a growth chamber at 25±2 ºC, photoperiod of 16: 8 (L: D) and with the 55±5 % relative humidity. Seed from the tomato cultivar ‘CH-Falat’ were sown into the pots (5×10 cm), containing different growth media. The three growth mixtures tested were: (i) 100% BAGA (sterile plant growth media); (ii) 70% BAGA with 30% pistachio waste vermicompost; (iii) 70% BAGA with 30% cattle manure vermicompost. After the bushes reached the 2- 4 leaf stage the bioassay tests were done by using the leaf-dip method. After drying of leaves, 20 adults of B. tabaci (24h) were released into each pot. The mixture of ethanol and distilled water (1:10) was as a control. After 72 h, mortality was recorded. To determine the effects of the sub-lethal dose (LC25) on the developmental durations of B. tabaci, the tomato pots that were prepared as above mentioned, dipped into LC25 concentration of each extract and abamectin, for 5s. After the drying of leaves, 15 pairs of B. tabaci adults were released in the pots and the cage was covered on the pot immediately. B. tabaci were removed from the plants after 72 hours and only the eggs less than 24 hours old were kept for the recording of the different stages of B. tabaci.

Based on the results, the kind of growth media was effective in the influence of extracts and abamectin, and the least LC50 of each insecticide was recorded in growth media that was added by pistachio waste vermicompost. Among the extracts, Aloe vera and leave of R. communis extracts showed the best and lowest effect against the B. tabaci with LC 50 value of 0.855 g/l and 22.841 g/l respectively (in pistachio waste vermicompost media). Subletal (LC25) effects of treatments on biological parameters of B. tabaci were significant compared to the control plant (p<0.05). Based on the results, the most mortality (%) in egg (22.84%), nymphal (42.11%) and pupal (11.94%) periods of B. tabaci was recorded for abamectin, Aloe vera and S. alopecuriodes extracts respectively. The interaction between vermicompost and extract was significant, and the longest of the nymphal period (19.83±0.67 days) was recorded on whiteflies that were treated by R. communis and reared on tomato plants grown in pistachio waste vermicompost. The shortest of this period (11.14±0.34 days) was recorded on control plant that grown in BAGA. Taken together, the longest development time was recorded on whiteflies that treated by S. alopecuriodes and reared on tomato plants grown in pistachio waste vermicompost and the shortest of this period was on insects treated by Aloe vera extract and pistachio waste vermicompost media. Plants fertilized with pistachio waste vermicompost had significantly higher phenolic content (10 mg/mL) than control (BAGA) (6.08 mg/mL), while those in cattle manure vermicompost group exhibited intermediary value (7.28 mg/mL).

These results indicated that the concomitant use of extract and vermicompost was more effective for controlling of B. tabaci. The most mortality caused by Aloe vera extract and amending of pistachio waste vermicompost into growth media increased its effectiveness. So, these extract and vermicompost can play an important role in the managing of B. tabaci in greenhouse crops.

The initial step to mass production and commercialization of native entomopathogenic fungal isolates includes collection as well as evaluation of their pathogenesis on the pest. This research aims to investigate the pathogenicity of 36 local fungal isolates collected from the Iranian Research Institute of Plant Protection, Tehran, Iran against greenhouse whitefly Trialeurodes vaporariorum. Due to the variation of the collected isolates volume, a preliminary screening test carried out on the fourth instars of a model insect Galleria mellonella. Based on the obtained results, the Beauveria bassiana A1–1 isolate showed the highest mortality with an average of 75%, followed by IRAN1787C, IRAN1751C, IRAN1395C, IRAN428C and IRAN441C with mean mortality rates of 57.50, 55, 52.50, 50 and 45%, respectively. Subsequently, the isolates were selected for evaluation of vegetative growth, sporulation and bioassay tests on greenhouse whitefly. In the bioassay test, five concentrations of the isolates (104, 105, 106, 107 and 108 conidia/ml) were tested on the third–instar of whitefly nymphs, and then the parameters LC50 and LT50 of the isolates were calculated. The highest vegetative growth rate belonged to IRAN428C, IRAN1395C, A1–1, IRAN1787C, IRAN441C and IRAN1751C isolates while the highest sporulation rate belonged to IRAN1787C, A1–1, IRAN428C, IRAN1395C, IRAN441C and IRAN1751C, respectively. The results showed that the A1–1 isolate indicated the lowest LC50 and LT50 values among all used concentrations. Moreover, its vegetative growth and sporulation ranked third and second among all the collected isolates, respectively. Therefore, the A1–1 isolate is being introduced as the most effective biocontrol agent to control greenhouse whitefly.

Sugarcane whitefly, Neomaskellia andropogonis Corbett (Homoptera: Aleyrodidae) is one of the important pests of sugarcane fields in Iran. In this study, the efficacy of two new insecticides including Sivanto® and Oberon Speed® was evaluated for controlling different life stages of whitefly on IRC99-02 and CP69-1062 sugarcane varieties under laboratory conditions. The concentrations of 20, 60, 100, 200, and 400 ppm of two insecticides were applied using leaf dipping method. The highest concentration of Sivanto® (400 ppm) caused 67.9% mortality on whitefly eggs in IRC99-02 variety; while Oberon Speed® did not show much ovicidal activity. Sivanto® effectively controlled the adult’s stage and the highest mortality percentage (90%) was observed at 400 ppm in IRC99-02 variety of sugarcane. While at the same concentration, Oberon Speed® caused 60 and 70% mortality in IRC99-02 and CP69-1062 varieties, respectively. Both insecticides were effectively controlled whitefly nymphs and pupae. Our results indicated that both of the insecticides had high toxicity on sugarcane whitefly. Also, parasitoid wasps were compatible with the insecticides and applied insecticides did not negatively affect their parasitism activity.

Whiteflies (Homoptera; Aleyrodidae) are the key pests of agricultural crops worldwide. Two species, which seriously damage crops, are the Silver leaf whitefly “Bemisia tabaci (Gennadius)” and the Greenhouse whitefly “Trialeorodes vaporariorum (Westwood)”. These pests are active on the underside of the leaves where they are relatively protected from insecticide. Moreover, emergence of resistant biotypes of whitelies impose much more costs on its chemical control. Therefore, during falling the past population, several researches have been carried out to find and use efficient biocontrol methods. One of the biocontrol agents to control B. tabaci is “Eretmocerus mundus” (Hy., Aphelinidae). The parasitoid should be introduced to control pest in the greenhouses. One of the methods, which is used in introducing of biological control agents, is ‘Banker Plant System’. In this system, the host plant has a population of reproducing natural enemy used as a reservoir. Therefore, as soon as the pest infection occurs, the parasitoids can find them and control the damage. İn a banker plant system, several aspects should be considered. Some of the behavioral and biological aspects are important. For example characteristics of leaf surface influence on the host finding time of the parasitoid. The biochemical characteristics of the host plants affect the parasitoid fitness. Therefore, we tried to compare these aspects of E. mundus in two host plants (eggplant and cotton) from banker plant point of view, to control B. tabaci in the greenhouses.
The two host plants (eggplant and cotton), were planted in the greenhouse and a culture of B. tabaci was reared on the plants. After two weeks, some of the infested plants were put in separate cages, and the parasitoid, E. mundus, that was collected from the egg plant and cotton fields of the Varamin region were released on the plants. Then, the biological characteristics of the parasitoid were evaluated on the two different host plants. The sex ratio was recorded in two different ways; 1) 100 pupae developed on each plants were put in vials, and 2) the wasps that emerged daily from collected leaves. In the next experiment, a leaflet of each host plant (2.5  3 cm), that was infested with the second and third stages of B. tabaci), was fixed upside down on a piece of wet cotton in a Petri dish. Then, a female parasitoid was release on each to record the host finding time for one minute. Finally, the four female parasitoids were released on an infested host plant for 48 hours, then the wasps were removed and the plants were kept in a climate room. Two weeks later, the leaves were collected and put up side down on cotton pieces in Petri dishes and the duration of the larval stages, the mortality and the number of females and males that come out from them were recorded for the two hosts.
In total, 438 wasps form the eggplant leaves and 297 from cotton leaves were collected, while 14 and 17 dead pupa were recorded on them, respectively. The data analysis did not show significant differences between them. In host finding experiment, 9 of 15 parasitoids could find the host during one minute on the eggplants leave, whereas, all female parasitoids could find the host on cottons leave, which was significantly different (P value of Fisher's exact test= 0.01689). In the biology parameter experiments on leaves, 192 parasitoid wasps form cotton and 158 from eggplant leaf were collected that were not significantly different (F=5.6; p=0.026). In contrast, on whole plant experiment, 156 wasps (76 females and 80males) from cotton plants and 134 wasps (66 females and 68 males) from eggplants were collected that were not significantly different (f=1.2; P= 0.32).
The results showed that the number of parasitoid and the sex ratio were not significantly different between two host plants, whereas the movement and searching activity of the parasitoid were better on cotton than eggplant. Base on the results and all of the factors that were considered in this work, eggplant could be a good host in a banker plant system for Bemisia tabaci and its parasitoid Eretmocerus mundus.

Greenhouse whitefly, Trialeurodes vaporariorum (Westwood), is an important pest of greenhouse throughout the world that causes serious damage on agricultural products. In this research, some biological parameters of the pest were studied in four cucumber cultivars (Royal Sluis, Soltan, Negin and Vida) at two heights (60 and 90 cm) in a greenhouse at 19-26 °C and 80% ± 5 RH. The developmental time of all immature stages were 27.49 ± 0.34, 28.23 ± 0.3, 26.63 ± 0.24 and 27.44 ± 0.3 days, in all cultivars, respectively, but it was slightly longer at the height of 90 cm compared to 60 cm (28.65 ± 0.24 vs. 26.43 ± 0.14 days, respectively). The preimaginal mortality percent ranged from 4 to 7% in different treatments, although this difference was not significant. Female longevities were 27.9 ± 0.67, 21.35 ± 0.34, 26.71 ± 0.6 and 22 ± 0.46 days in the cultivars, respectively (P < 0.01). It was also averaged as 23.29 ± 0.4 and 26.4 ± 0.66 days at both heights. The number of eggs / female were 203.82 ± 4.89, 132.26 ± 3.57, 210.68 ± 5.31 and 162.79 ± 5.15 in different cultivars with an average of 167.66 ± 5.68 and 187.98 ± 4.75 in 90 and 60 cm (P < 0.01). The sex ratio showed no significance among the cultivars at all heights.

Tomato yellow leaf curl virus, TYLCV belongs to the family Geminiviridae and Begomovirus genus (27). In recent years, extensive damage to tomatoes and cucurbits plants in the south and the southeast of Iran has arrived (23). This virus family have circular, and single-stranded DNA genome and are widespread in tropical and subtropical areas (30). They are infected several plant species with economic importance. Begomoviruses are dicot-infecting, whitefly-transmitted viruses with a genome comprised of one or two molecules DNA (5). Up to now, studies have been performed to evaluate the status of distribution, and identification of natural host and assess the genetic diversity, but there is not a comprehensive review about its weed hosts yet. In this research, The weeds from margins and inside greenhouses and farms of tomato and cucurbit in severely infected areas including Manoojan, Kahnooj, Faryab, Anbrabad and Jiroft to identify weed hosts of the virus in nature, were collected. Identification of collected samples were conducted by botanical specialists. Total DNAs were extracted from leaves according to the method of zhang et al. (1998) and stored at -20 oC. Identification of infected samples were carried out by PCR using degenerate primer pairs PCRv 181/Bc that direct the amplification of˷ 550 bp fragment of mono – and bipartite begomoviruses genome comprising the C-terminal portion of the intergenic region (IR) N-terminal portion of the CPgene. PCR were performed in 25 µl reaction volumes containing 1 µl of template DNA, o.5 µl of Taq DNA polymerase Sinaclon (IRAN), 1.2 µl MgCl2, 0.5 µl dNTPs. 1 µM of each forward and reverse primers, 4.3 µl of 10× reaction buffer and 15.5 distilled water. The amplification were performed using a peqSTAR 96x Termal Cycler (Peqlabe, Germany). PCR conditions consisted of initial denaturing 94 oC for 3 min followed by 30 cycles of denaturation at 94 oC for 50s, annealing at 55 oC for 60s, and extension at 72 oC for 1 min followed by 1 cycle at 72 oC for 10 min. Electrophoresis of polymerase chain reaction products on 1% agarose gel was performed and stained with DNA safe stain (sinaclon-IRAN). The polymerase chain reaction product were sequenced using automatic sequencer AB13730XL (Macrogen, Korea). The resulting sequences were looking similarity and after obtaining a degree of homology, 550 bp fragment of the coat protein gene of four isolates were ordinated by Bio Edit software. Looking for similar sequences were obtained and then achieved the 550 bp fragments of the coat protein gene homology four software isolates Bio edit (21) were ordination. To study the phylogenetic relationship of study strains, the phylogenetic tree was drawn with maximum likelihood way in the MEGA 5 software. Then percentage of similarity at the nucleotide and amino acid sequence with a genetic distance matrix was determined by using the software CLC Main work bench. The results showed that four weeds including Chrozophora tinctoria, Heliotropium annum, Malva neglecta and Chenopodium murale were infected with TYLCV. To compare the TYLCV isolates in infected weeds, 550 bp fragment of the coat protein gene in four different strains of the virus was sequenced. Assessment of the genetic similarity between study isolates and strains in the Gene Bank revealed that study isolates with isolates from Gene Bank have similarity in the range of 93/24-99/98% at the nucleotide level and in the range of 87/42-98/15% at the amino acid level. Sixty-six mutations at the nucleotide level in compared sequences in this study was also found. Drawn Phylogenetic tree was confirmed the results of the genetic distance matrix. The results showed that the virus has a wide host range, and identification of weed hosts to remove the maintenance of virus plays an important role in the epidemiology of the disease. and also it’s the management of this disease. This is the first report from Malva neglecta and Chenopodium murale as weed host of TYLCV in Iran. TYLCV causing major damage to the cultivation of tomatoes. Infection caused by it in the South and South East farms in Iran is usually very widespread. Because of the subtropical climate in these areas that is essential for the activity and proliferation of whitefly vector, this virus can cause a high damage in these areas (34). High genetic variability in begomovirus populations infecting different non-cultivated hosts has been reported (28, 35, 38). Conversely, begomovirus populations infecting cultivated hosts seem to have lower variability (6,14,41,43).Wild/non-cultivated plants from different botanical families can sustain a high species diversity of begomoviruses and can play an important epidemiological role serving as alternate/reservoir hosts, preventing local extinctions of the virus when the cultivated host is absent (1, 14). In these cases, whiteflies transmitting begomoviruses between cultivated and non-cultivated hosts contribute to virus evolution and disease epidemics (1, 34). Weeds and plant host of indigenous origin and imported ones can be by a large number of plant viruses including Begomoviruses infectedwhich are as reservoirs host of the virus, the primary focus for infection of crops, and play a pivotal role in the emergence of new viral strains (35). Identification and control of the weeds have an important role in disease management. Relatively high incidence of the virus in the weeds with a high density of whitefly population throughout the year, requires new management guidelines. The results showed that the virus has a wide host range, and identification of weed hosts to remove the maintenance of virus that play an important role in the epidemiology of the disease, in the management of this disease is important. This is the first report from Malva neglecta and Chenopodium murale as weed host of TYLCV in Iran.